This application incorporates by reference in its entirety pending U.S. provisional Pat. application entitled DENTAL IMPLEMENT FOR TOOTH RESTORATIONS, Ser. No. 60/355,578, filed Feb. 7, 2002.
The present application relates to a dental implement and, more particularly, to a retaining device, which is used to separate teeth and, further, to hold a contour band in place around a tooth when a cavity in the tooth is to be filled.
When a tooth includes a decayed portion, the decayed portion is excavated and then filled. When the decayed portion is located near its interproximal area between an adjacent tooth, the tooth structure is usually insufficient to provide support to the filling material during the filling process. In order to retain the filling material in the cavity while it hardens, a tooth reconstruction element (typically a thin band, which is usually made of stainless steel or the like) is positioned about the tooth and is secured tightly about the tooth such that the element forms an outer shell or matrix. In this manner, the reconstruction element allows the filling material to fill the excavated portion of the tooth and harden into the correct shape. In addition, in order to accommodate the thickness of the reconstruction element and the shrinkage of the filling material (typically a composite resin) as the filling material cures, the adjacent teeth must be separated.
Numerous implements have been developed to separate teeth and to hold bands in place about a tooth. For example, open-ended rings, such as described in U.S. Pat. No. 6,336,810 to Bertoletti and U.S. Pat. No. 6,325,625 to Meyer, are positioned around the tooth and include downwardly extending tines that are urged between the teeth to separate the teeth and, further, to secure the band against the selected tooth. In order to position the ring, the tines are separated, which causes the ring to generate an inward spring force. However, when the tines are moved between their initial, unloaded state to their separated, loaded state, over time, it has been found that these rings undergo significant and appreciable plastic deformation and, consequently, lose their resilience and strength. Therefore, over time, the rings lose their ability to generate a sufficient force to properly hold the band in place against the tooth and, further, to generate sufficient force to separate the teeth.
Consequently, there is a need for a retaining device that will generate a sufficient force to separate the teeth and hold a band in place against a tooth while retaining its resilience over greater period of time so that it can be used repeatedly.